Faisal Nimri

Al-Mohtaseb

Mo Alfarra

7

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→ The peritoneal recesses and fossae

In certain parts of the abdomen (At the junction between intraperitoneal and retro

peritoneal organs) the transition from retroperitoneal organ to an intraperitoneal one

creates a fold of peritoneum; this fold may have a recess or fossa beneath it.

From a surgical point of view the omental bursa can be considered to belong to this

category, with its opening at the epiploic foramen, bounded in front by the free border

of the lesser omentum.

These recesses are of surgical importance since they may become the site of internal

hernia, that is, a piece of intestine may enter a recess or fossa and if there is pressure

on the walls of the intestine, internal hernia will become strangulated hernia (the

intestine is constricted or strangulated by the peritoneal fold granding the entrance to

the recess).

The cut of the blood supply in strangulated hernia will cause gangrene (degeneration of

cells) in the part of the small intestine that is herniated, and this requires urgent surgical

intervention where we remove the gangrenous part of the small intestine and connect

the two healthy parts together.

A person with internal hernia (especially kids) will have a feeling of discomfort and slight

pain but if it progresses to strangulated hernia there will be severe pain.

The recesses are sometimes found in relation to the duodenum (retroperitoneal except

first and last inches so there are recesses around it), cecum (cecum is retro ileum is

intra) and sigmoid colon (intraperitoneal but the descending colon is retro so recesses

may form).

1- Duodenal recesses or fossae

The superior duodenal recess or fossa

The inferior duodenal recess or fossa

The paraduodenal recess or fossa

The duodenojejunal recess or fossa

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2- Cecal recesses

The superior ileocecal or fossa

The inferior ileocecal or fossa

The retrocecal recesses or fossa (most important one and where we frequently find

the appendix)

The rectocolic recess or fossa

3. The Intersigmoid Recess (formed by the inverted V attachment of sigmoid

mesocolon)

Folds and recesses of posterior abdominal wall:

superior duodenal fold and recess

inferior duodenal fold and recess

Intersigmoid recess.

4- Hepatorenal recess (Morison’s pouch)

lies between the right lobe of liver, right kidney,

and right colic flexure, and is the lowest parts of

the peritoneal cavity when the subject is supine.

Sometimes in the case of appendicitis, if rupture

occurs the pus may gather there, and abscess will

form (we have to drain the abscess).

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→ Pouches

In the lesser pelvis, the peritoneum dips downwards forming a larger fossa, named

, the clinical importance of the pouches is the fact that they are a potential site for pouch

internal abdominal hernia.

In males

Rectovesical pouch (between the rectum and urinary

bladder or the seminal vesicles and ampulla ductus

deferents)

rdRemember that the peritoneum covers the upper 3

of the rectum completely (except posterior wall) and

covers the rest of the rectum anteriorly then it covers

the upper surface of the urinary bladder creating a pouch between the rectum and the

urinary bladder.

Internal hernia may happen here but not as common because it is wide.

The retrovesial pouch is the lowest part of the peritoneal cavity in anatomical position

in male.

In females

2 pouches

1- Rectouterine pouch or Douglas pouch (between

rectum and uterus)

2- Vesicouterine pouch (between bladder and

uterus)

- The rectouterine pouch is formed between the anterior surface of the rectum and the

posterior surface of the uterus and the upper part of vagina.

- The Vesicouterine pouch is formed between the anteroinferior surface of the uterus

and the superior surface of the urinary bladder.

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→ Peritoneal subdivision

The transverse colon and transverse

mesocolon (remember that it is bound to the

anterior border of the pancreas) divides the

greater sac into

- Supracolic compartments (above transverse

colon and mesocolon).

- Infracolic compartments (below transverse

colon and mesocolon).

- Rt.extraperitoneal space ( bara area of liver &

diaphragm).

Supracolic compartments

Divided to:

- Subphrenic space

- Subhepatic space

Remember what we said above about appendicitis and Morison’s pouch (which is

between the liver, right kidney and right colic flexure)

If acute appendicitis progresses to chronic, abscess formation will occur and in case of

rupture the pus could reach Morison’s pouch or to the right subdiaphragmatic

(subphrenic) space further spreading the infection and formation of other abscesses in

(notice in the picture have to be treated via drainage ll occur which these spaces wi

above the arrows and how there is a connection between the location of the appendix

and the aforementioned spaces).

The patient in this case would have unstable temperature that goes up and down and

sleep on his right side and on his back and wouldn’t eat. You could diagnose the issue

based on his history if he had untreated acute appendicitis.

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. (subdiaphragmatic) Subphrenic space

between the anterior part of the liver and the space peritonealis a subphrenic space (The

superiorly -diaphragm, separated into right and left by the falciform ligament, and postero

)bounded by the coronary ligament.

Divided by the attachment of Falciform ligament into

Right subphrenic space (abscess formation is more common here than in the left

space because it is more open, check the picture with the arrows above)

Left subphrenic space

Subhepatic space

divided into:

Right subhepatic space (Morison’s pouch)

Left subhepatic space (lesser sac)

Infracolic compartments

When a person is sleeping on his back fluid in

the abdomen will gather in 2 cavities, one in

the abdomen and one in the pelvis.

If the person is setting up fluid will gather in

the pelvis.

The reason why the fluid descends to the pelvis

is the presence on paracolic gutters (more details below)

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The infracolic compartment lies below the transverse colon and transverse mesocolon.

Divided by root of the mesentery of small intestine into:

- Rt. Infracolic compartment (closed from the pelvis by

the mesentery)

- Lt. infracolic compartment (open to the pelvis)

We know that the ascending and descending colons are

retroperitoneal, but the peritoneum not only covers

their anterior surfaces but also covers their sides and

fixes them to the posterior abdominal wall, and the

attachment of the peritoneum to the post. abdominal

wall creates the gutters or sulcus on the sides of the

colons, and these gutters or grooves are what allow

movement of fluid in the abdominal cavity (think of

them like rivers).

Right paracolic sulcus (gutter)

Subdivided into:

- Right medial paracolic gutter (closed from above and below)

- Right Lateral paracolic gutter (Open, communicates with the hepatorenal recess and

the pelvic cavity and provides a route for the spread of infection between the pelvic and

the upper abdominal region, notice the arrows in the picture).

Left paracolic sulcus (gutter)

Subdivide into:

- Left medial paracolic gutter

- Left Lateral paracolic gutter

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Left lateral paracolic gutter separated from the area around the spleen by the

phrenicocolic ligament (a fold of peritoneum that passes from the colic flexure to the

diaphragm), and this ligament prevents the spreading of infection upwards.

Left medial paracolic gutter is also separated from that area by the transverse colon and

mesocolon which they prevent the separation of infection upwards (again, notice the

arrows in the picture above).

Both of those gutters communicate with the pelvis and are open to the outside through

it.

Small Intestine

The small intestine is made up of 3 parts

and last inches. stexcept 1 and is retroperitoneal(10 inches) duodenum which is 25cm -

- jejunum and ileum which are 6 meters long and are intraperitoneal (they have a

mesentery).

Duodenum

The duodenum is a c-shaped concave tube about

10” in length.

is rdis 3 inches, 3 ndis 2 inches, 2 st(has 4 parts the 1

is 1 inch. th4 inches and the 4

It joins the stomach to the jejunum.

The pancreas has a tail, body, neck (the portal vein

forms behind the neck, from splenic and superior

mesenteric veins and continues to the liver) and

head and the duodenum curves around the head of

to the left and backwards.the pancreas

(notice the location of the Uncinate process of the

head, left of the duodenum and the superior

mesenteric artery and veins pass in front of this process).

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Most of the duodenum is retroperitoneal except the 1st inch & last inch, this short

segment (1st inch) has the lesser omentum on its upper border, the greater omentum

on its lower border, and the lesser sac posterior to it.

The duodenum begins at the pyloric sphincter and ends at the ligament of Treitz which

continue as jejunum.

eives the opening of theit rec part of ndthe 2 is important becauseThe duodenum

common bile and pancreatic ducts (that secrete substances to

complete the digestion of fat which happens in the duodenum).

The common bile duct and the pancreatic duct have the same

opening in the duodenum. When they meet, they form a bulge

in the duodenal wall called ampulla of vater, around it a

sphincter called sphincter of Oddi (a smooth muscle), and we

call the opening from inside the major duodenal papilla,

sometimes there is another opening 1 inch above the major

papilla for accessory pancreatic ducts called minor duodenal

papilla.

The duodenum is situated in the epigastric and umbilical

regions.

The liver has left and right lobes, and the left and right

hepatic ducts form the common hepatic duct which meets

with the cystic duct of the gallbladder to form the common

bile duct.

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part of the duodenum st1

The first part is 2 inches long, and is divided into two parts

)duodenal ulcers\peptic(intraperitoneal, common site of The first inch*

ulcers are more common than gastric ulcers and happen because the duodenal :Note

chyme that comes from the stomach is acidic (the duodenal secretions are alkaline and

work to neutralize that acidity, but ulcers could still happen if the acidity was too high),

the posterior wall of duodenum is affected most.

*The second inch (retroperitoneal)

- It begins from the pyloduodenal junction.

- At the level of the transpyloric line.

.to the rightlumbar vertebra 1 inch stat the level of the 1 sbackwardand supwardRuns -

Some histology

The GI track has 4 layers (mucosa, submucosa, muscular layer and adventitia or

serosa)

The folds on the inside of the duodenum are called plicae circulares.

The lining epithelium of the duodenum is simple columnar epithelium with goblet cells.

In the submucosa of duodenum there are glands called Brunner’s glands that produces

the alkaline secretion that neutralizes the acidity of the chyme when it comes from the

stomach.

In the entirety of the GI track only 2 organs have glands in their submucosa, and :Note

they are the esophagus and duodenum.

In the mucosa of the duodenum (which is like mentioned above simple columnar with

r of loose (areolar) connective tissue, which lies is a thin laye( lamina propria goblet cells) there isbeneath the epithelium, and together with the epithelium and basement membrane constitutes the

.ieberkühnLcrypts of which also contains glands called mucosa, from the web)

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Endoscopic retrograde cholangiopancreatography)( PERCThe doctor discussed

proceedsThis is a new technique where an endoscope is placed through the mouth and

through the pharynx, esophagus, stomach and duodenum and then you retrogradely

find the major duodenal papilla and you cut the sphincter of oddi and you enter either

the pancreatic or common bile ducts based on what you want to do.

f stones that form in the common bile duct and This technique is used in treatment o

which was treated block it and this causes jaundice (yellow sclera, yellow and itchy skin)

basketa use you with the endoscope , when you find the stonewith surgery in the past

t in the duodenum and it gets out with the stool.and remove the stone and leave i

Sometimes stasis of the secretion of pancreas happens and it becomes like mud or

forms stones and closes the pancreatic duct and may cause pancreatitis which is very

by entering the duct with the endoscope and dangerous, and it is treated with ESRP,

adding saline with will dissolve the stones.

part of the duodenum stRelations of the 1 →

Anterior relations

The liver (quadratus lobe)

gall bladder

Superior relations

Epiploic foramen (anterior to it there is a free edge

of lesser omentum contains common pyloric duct,

hepatic artery and portal vein)

Posterior relations

- The lesser sac

- the Bile duct

- portal vein

- I.V.C

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inch st(if there is a peptic ulcer on the posterior wall of the 1 gastroduodenal Artery -

perforation and infiltration o may occur along with bleeding from the artery)

Inferior relations

The head of the pancreas

part of the duodenum nd2

It is 3 inches long, runs downward vertically on the

right side in front of the Right kidney and right

lumbar thand 4 rdnext to the 3ureter and ends

vertebrae.

Halfway of it, the bile duct and the main pancreatic

duct pierce the medial wall, and then form the ampulla that opens in the major

duodenal papilla. The accessory pancreatic duct (if present) opens in the minor

duodenal papilla more superiorly.

part ndRelations of the 2 →

Anterior relations

• The gallbladder (fundus)

• Right lobe of the liver

• Transverse colon

• coils of small intestine.

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Posterior relations

• Hilum of Right Kidney

• Right Ureter.

Lateral relations

• Right colic flexure

• Ascending colon

• Right lobe of the liver.

Medial relations

- Head of pancreas

- Bile and pancreatic ducts.

part of the duodenum rd3

4 inches long

• Runs horizontally to the left, in front of the

vertebral column

• On the subcostal plane.

• Under the lower margin of the head of

pancreas

• Above the coils of the jejunum.

part of duodenum rdRelations of 3 →

Anteriorly:

The root of the mesentery of the small intestine

the superior mesenteric vessels contained within the mesentery coils of jejunum

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Posteriorly:

The right ureter

The right psoas muscle

The inferior vena cava

The aorta

Superiorly:

The head of the pancreas

Inferiorly:

Coils of jejunum

part of duodenum th4

1 inch long

Runs upward to the left

to the inch lumbar vertebrae 1 ndin the duodejejunal junction at the level of the 2 sndE

left.

The junction (flexure) is held in position by the ligament of Treitz, which is attached to

the right crus of the diaphragm (duodenal recess).

part of duodenum thRelation of 4 →

Anterior

- The beginning of the root of the mesentery

- coils of the jejunum.

Posterior

- Lt. psoas major

- the sympathetic chain on the left margin of the aorta.

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Superior

- Uncinate process of the pancreas.

Blood supply of the duodenum

Arteries

superior part) is supplied by the nd1/2 of 2 part + upper st(1he upper half T -1

pancreaticoduodenal artery, a branch of the gastroduodenal artery (from celiac trunk).

inferior part) is supplied by the th+4 rdpart +3 ndof 2 (lower ½The lower half -2

pancreaticoduodenal artery, a branch of the superior mesenteric artery.

What separates the upper from lower half?

- The major duodenal papilla and sphincter of Oddi.

*Remember that in embryology the GI track is divided to the:

- foregut (esophagus (lower part), stomach and upper half of duodenum)

Blood supply of foregut → Celiac trunk of abdominal aorta

- midgut (from lower half of duodenum to lateral\distal third of transverse colon)

Blood supply of midgut → Superior mesenteric artery

- hindgut (from distal third of transverse colon to rectum)

Blood supply of hindgut → Inferior mesenteric artery

Veins

The superior pancreaticoduodenal vein

drains into the portal vein.

The inferior vein joins the superior

mesenteric vein.

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Lymphatic drainage

• The lymph vessels follow the arteries

• drain upward → via pancreaticoduodenal nodes → the gastroduodenal nodes → the

celiac nodes.

• drain downward → via pancreaticoduodenal nodes → the superior mesenteric nodes

around the origin of the superior mesenteric artery.

Nerve supply (will be discussed in detail with the rest of the small intestine)

• Sympathetic nerves

• parasympathetic nerves from:

1- The celiac plexus.

2- Superior mesenteric plexus.